Preparation for cleaning metal preparatory to painting



UNITE .JAMES D. GER AND GLETE L. BOYLE, DETROIT, MICHIGAN.

Ho Drawing.

This invention relates to an improved composition to be employed in the cleaning of metal, chiefly sheet steel preparatory to painting thesame, and is particularly used in connection with the cleaning of sheet metal that is employed in the fabrication of automobile bodies, steel cabinets and other articles similarly fabricated.

An object is to provide a cleaning composition the vapor tension of which is such that a minimum amount of evaporation of the solvent occurs.

Heretofore cleaning compositions intended for this employment have included a rust attacking and removing acid, such as phosphoric or sulphuric and an oil solvent such as ethyl alcohol, butyl alcohol, acetone, ethyl methyl ketone, and the like. Some of these solvents possess excellent solvent properties for the oil and grease found on the metal to be cleaned, but as a class their vapor tension is high and the evaporation thereof inuse is rapid. It has not been possible therefore to commercially employ such solvents in a hot condition with satisfactory results notwithstanding the fact that if the solvent is employed in a hot state it is much more reflective as a cleaner.

The purpose of this invention is to provide a composition capable of attacking and removing the accumulated rust, oil and grease which is found on the metal, which composition may be applied in a heated state without appreciable evaporation of the solvent for the oil and grease.

The glycols have a low vapor tension but are not very efiective as solvents for the purpose. However, we have found that certain 'derivatives of certain gycols, such as the ether de- 40 rivatives of ethylene, glycol, are highly satisfactory as a solvent for the oil and grease found on metals ofthe character hereinabove referred to and also have such a vapor tension as to be particularly adapted for this use. We prefer to employ mono-ethyl ether of ethylene glycol. This particular solvent is readily miscible with the acids which would be employed in conjunction therewith in any desired proportion; it is stable in such an acid solution and other diluents may be employed in comunction therewith. We have found a PREPARATION FOR CLEANING METAL PBEPARATORY TO ram'rrne. I

' Application filed September 22, 1927. Serial No. 221,395.

mixture ofthe following character to be particularly suitable for the purpose:

Form/ale I Per cent by volume. 85% orthophosphorlc acid Water I 30 Mono-ethyl ether of ethylene glycol 35 more than 15% of such other diluents should be used.

The following formula is submitted as being very satisfactory as asolvent though incapable of being used at the high temperature at which the first formula may satisfactorily be used:

Formula II.

. Per cent by volume. v orthophosphoric acid Water 30 Ethyl methyl ketone... 10 Mono-ethyl ether of ethylene glycol 25 The first formula may be applied at any temperature up to 150 F. While the second formula or other formulas containing the more volatile diluents should not be applied at a temperature higher than 100 F.

In the cleaning of the metal the same may be painted or sprayed with cleaning solution, and after allowing a limited period for such solution to act it should be rinsed or w'ashed from the metal with. hot water. If cold water is used it should be flowed on freely. In either case the metal is promptly dried and should be subjected to heat to thoroughly dry its pores before the priming coat of paint is applied to it.

The instant solution is highly satisfactory for the purpose for which it is intended and leaves the surface of the metal with a bright, clean finish.

What we claim is:

1. A. composition of matter to be used for cleaning steel for painting consisting offa rust removing acid and ethylene glycol.

2. A composition of matter. tobe used for cleaning metal preparatory to painting the metal including a rust attacking and removlg acid and an ether derivative of ethylene g yco v 3; A composition of matter to be used for cleaning metal preparatory to painting the the mono-ethyl ether of metal comprising, by volume approximately one-third each of z a rust attacking and remov g acid, an ether derivative of ethylene gly- 001, and a suitable diluent.

4. A composition of matter to be used for cleaning metal preparatory 'to paintingthe metal comprising orthophosphoric acid and an ether derivative 0 ethylene glycol.

5. A composition "of matter to be used for 20 cleaning'steel for paintin consistin of a rust removing acid and t e mono-ct yl of ethylene glycol in substantiall the propositions hereinset forth-in Forum a I.

"In testimony whereof, we sign this specification.

'. JAMES 'n-xmuenn. cpETE BOYLE. 

